DataFlex
DataFlex
PC/SC Wait for Smart Card Status Change (Inserted, Removed from Reader, etc.)
See more SCard Examples
Demonstrates how to synchronously wait for a status change, such as for a smart card to be inserted into a reader, or removed from a reader.Note: This functionality was introduced in Chilkat v9.5.0.87.
Chilkat DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoScard
Variant vJson
Handle hoJson
String sName
Variant vSbState
Handle hoSbState
Integer i
Integer iCount_i
Variant vStReaders
Handle hoStReaders
Integer iNumReaders
Variant vJson2
Handle hoJson2
Boolean iChanged
String sState
String sAtr
Integer iNumChanged
String sTemp1
Boolean bTemp1
Move False To iSuccess
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
Get Create (RefClass(cComChilkatSCard)) To hoScard
If (Not(IsComObjectCreated(hoScard))) Begin
Send CreateComObject of hoScard
End
// First establish a context to the PC/SC Resource Manager
Get ComEstablishContext Of hoScard "user" To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoScard To sTemp1
Showln sTemp1
Procedure_Return
End
// First we'll examine the state of all connected readers to see which have smartcards already inserted..
// Get JSON containing information about the smartcards currently inserted into readers.
// This also includes information about USB security tokens.
Get Create (RefClass(cComChilkatJsonObject)) To hoJson
If (Not(IsComObjectCreated(hoJson))) Begin
Send CreateComObject of hoJson
End
Get pvComObject of hoJson to vJson
Get ComFindSmartcards Of hoScard vJson To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoScard To sTemp1
Showln sTemp1
Procedure_Return
End
// When writing this example, I have 3 smart card readers plugged into my system.
// One of them has a smart card inserted.
// Here's the JSON returned by FindSmartcards...
// {
// "reader": [
// {
// "name": "Alcor Micro USB Smart Card Reader 0",
// "state": "empty"
// },
// {
// "name": "Generic Smart Card Reader Interface 0",
// "state": "present",
// "vendorName": "Generic",
// "serialNumber": "3230303730383138303030303030303030",
// "systemName": "Generic Smart Card Reader Interface 0",
// "card": {
// "atr": "3BFC180000813180459067464A00641606F2727E00E0",
// "windows": {
// "miniDriver": "tagliov70px.dll",
// "cryptoProvider": "Microsoft Base Smart Card Crypto Provider",
// "keyStorageProvider": "Microsoft Smart Card Key Storage Provider"
// }
// }
// },
// {
// "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
// "state": "empty"
// }
// ]
// }
Set ComEmitCompact Of hoJson To False
Get ComEmit Of hoJson To sTemp1
Showln sTemp1
Showln " "
// We can iterate over the JSON to find the readers with a smart card already inserted..
Get Create (RefClass(cComChilkatStringBuilder)) To hoSbState
If (Not(IsComObjectCreated(hoSbState))) Begin
Send CreateComObject of hoSbState
End
Move 0 To i
Get ComSizeOfArray Of hoJson "reader" To iCount_i
While (i < iCount_i)
Set ComI Of hoJson To i
Get ComStringOf Of hoJson "reader[i].name" To sName
Send ComClear To hoSbState
Get pvComObject of hoSbState to vSbState
Get ComStringOfSb Of hoJson "reader[i].state" vSbState To iSuccess
Get ComContains Of hoSbState "present" True To bTemp1
If (bTemp1 = True) Begin
Showln sName " has a smart card inserted."
End
Else Begin
Showln sName " does not have a smart card inserted."
End
Move (i + 1) To i
Loop
Showln " "
// Now let's begin the code to wait for a change (where a smart card gets inserted or removed)
// Get the list of all readers.
Get Create (RefClass(cComChilkatStringTable)) To hoStReaders
If (Not(IsComObjectCreated(hoStReaders))) Begin
Send CreateComObject of hoStReaders
End
Get pvComObject of hoStReaders to vStReaders
Get ComListReaders Of hoScard vStReaders To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoScard To sTemp1
Showln sTemp1
Procedure_Return
End
// Show the reader names..
Get ComCount Of hoStReaders To iNumReaders
Move 0 To i
While (i < iNumReaders)
Get ComStringAt Of hoStReaders i To sTemp1
Showln i ": " sTemp1
Move (i + 1) To i
Loop
// Sample output from the above loop.
// 0: Alcor Micro USB Smart Card Reader 0
// 1: Generic Smart Card Reader Interface 0
// 2: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
//
// Synchronously wait 30 seconds for a card to be inserted or removed from any of the above readers.
Get Create (RefClass(cComChilkatJsonObject)) To hoJson2
If (Not(IsComObjectCreated(hoJson2))) Begin
Send CreateComObject of hoJson2
End
Get pvComObject of hoStReaders to vStReaders
Get pvComObject of hoJson2 to vJson2
Get ComGetStatusChange Of hoScard 30000 vStReaders vJson2 To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoScard To sTemp1
Showln sTemp1
Procedure_Return
End
Showln " "
// Let's see what happened...
Set ComEmitCompact Of hoJson2 To False
Get ComEmit Of hoJson2 To sTemp1
Showln sTemp1
Showln " "
// This is what json2 contains.
// A card was inserted into the reader named "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0"
// The "numChanged" indicates that one reader's status changed.
// The "changed":true indicates the reader that changed. The state is now "present".
// {
// "numChanged": 1,
// "reader": [
// {
// "name": "Alcor Micro USB Smart Card Reader 0",
// "changed": false,
// "state": "empty"
// },
// {
// "name": "Generic Smart Card Reader Interface 0",
// "changed": false,
// "state": "present",
// "atr": "3BFC180000813180459067464A00641606F2727E00E0"
// },
// {
// "name": "SCM Microsystems Inc. SCR33x USB Smart Card Reader 0",
// "changed": true,
// "state": "present",
// "atr": "3BDF96FF8131FE455A018048494443313158587300011B09"
// }
// ]
// }
// Find the reader that changed...
Get ComIntOf Of hoJson2 "numChanged" To iNumChanged
Showln "number of readers with a changed state: " iNumChanged
Move 0 To i
Get ComSizeOfArray Of hoJson2 "reader" To iCount_i
While (i < iCount_i)
Set ComI Of hoJson2 To i
Get ComBoolOf Of hoJson2 "reader[i].changed" To iChanged
If (iChanged = True) Begin
Get ComStringOf Of hoJson2 "reader[i].name" To sName
Get ComStringOf Of hoJson2 "reader[i].state" To sState
Showln "Changed: "
Showln " reader name: " sName
Showln " new state: " sState
// If a card is now in this reader, we should have the ATR of the card..
Get ComHasMember Of hoJson2 "reader[i].atr" To bTemp1
If (bTemp1 = True) Begin
Get ComStringOf Of hoJson2 "reader[i].atr" To sAtr
Showln " ATR of card inserted into this reader: " sAtr
End
End
Move (i + 1) To i
Loop
// The output from the above loop:
// number of readers with a changed state: 1
// Changed:
// reader name: SCM Microsystems Inc. SCR33x USB Smart Card Reader 0
// new state: present
// ATR of card inserted into this reader: 3BDF96FF8131FE455A018048494443313158587300011B09
// Applications should always release the context when finished.
Get ComReleaseContext Of hoScard To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoScard To sTemp1
Showln sTemp1
End
End_Procedure